Syrian President Bashar Assad said in a Russian-TV appearance Tuesday night that he will not quit under pressure from the international community. Rebel groups and the Western-led coalition backing them say it's impossible for the embattled leader to lead a postwar Syria after more than four years of civil war.

The president "comes to power with the people's assent through elections, and if he leaves, he leaves if the people demand it,” Assad said. He was re-elected in 2014 with 88.7 percent of the vote. But the voting took place only in government-held areas and the opposition said it had no credibility in the midst of a civil war.

Assad also admitted during the TV interview that his government was being assisted by Iran "politically, economically and militarily," but he denied claims that his allies in Tehran had troops on the ground.

Assad's comments come during a period of intrigue as Russian warships and planes deliver military equipment into the country. It's unclear as yet what Moscow's intentions are for the equipment, although the Russians are denying they will attack the Islamic State group, which currently controls more than half of Syria's territory and has claimed an attack on a military base in the North Caucasus of southern Russia.

Touching on the refugee crisis that has seen more than 4 million people flee the country, Assad blamed "terrorism" and called on Western governments to stop funding rebel groups that he blames for the surge of displaced Syrians into neighboring countries and Europe.

U.S. Secretary of State John Kerry called his Russian counterpart, Sergey Lavrov, Tuesday in an attempt to work out why Russia was building its forces in Syria. Kerry said the continued support of Assad "risks exacerbating and extending the conflict," a statement said.

Pentagon officials said Monday it was clear that Russia was establishing a “forward operating base” at an airport in Latakia, the main port on Syria’s Mediterranean coast.